In this task, you will be presented with a passage and have to answer a question based on your understanding of the events inferred from the passage. Try to find the best answer that is most likely to fill in "_". Note that the URLs in the text have been replaced with [Link].

Over one hundred million people play Minecraft on their computers, but soon there will be a mind-blowing new way to experience the video game. Microsoft has shown off how Minecraft can be played using its HoloLens headset, conjuring a holographic city built from tiny virtual bricks on a coffee table. The game can be played on any surface and the headset allows people to play collaboratively in an entirely new way. Microsoft demoed its technology at E3 - the world’s largest annual video game conference - held in Los Angeles, where it shared footage of forthcoming Xbox One games including Halo 5: Guardians, Gears of War 4 and Tomb Raider.Microsoft debuted holographic game features at E3 in Los AngelesMinecraft can be played on any surface using the HoloLens headsetEnables players to create 3D holographic cities on a tabletop, manipulate cities with their hands and voice and reveal underground chambersThere is no news on when the headset and accompanying game will launch 
 Question:Otherwise, viewers could only see a man waving wearing _.
HoloLens